Survival and induction of the SOS system by 5-azacytidine, an analog of cytidine, were studied in Escherichia coli K-12. This compound did not produce any effect on the viability of dcm and dam dcm mutants. Furthermore, recA430 and lexA1 strains (both mutations interfere with LexA repressor cleavage but not recombination proficiency) were more resistant than the wild-type strain of E. coli K-12. In contrast, recBC and recA13 mutants were more sensitive to 5-azacytidine than the wild type. Transient exposure of E. coli to 5-azacytidine for 60 min induced both recA-dependent inhibition of cell division and induction of lambda prophage in Dcm+ strains but not in Dcm- mutants. Expression of both functions was dependent on recBC exonuclease. On the other hand, 5-azacytidine was unable to trigger the induction of umuCD and mucB genes and no amplification of RecA protein synthesis in either Dcm+ or Dcm- strains was observed. These last results are in agreement with previously reported data suggesting that there is a discrimination in the expression of the several SOS functions and that some SOS genes may be induced without amplification of RecA protein synthesis.
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http://dx.doi.org/10.1016/0167-8817(86)90035-0 | DOI Listing |
ACS Infect Dis
January 2025
Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States.
Carbapenemase producing (CPEs) represent a group of multidrug resistant pathogens for which few, if any, therapeutics options remain available. CPEs generally harbor plasmids that encode resistance to last resort carbapenems and many other antibiotics. We previously performed a high throughput screen to identify compounds that can disrupt the maintenance and replication of resistance conferring plasmids through use of a synthetic screening plasmid introduced into K-12 cells.
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December 2024
Research Department for Limnology, Mondsee, Universität Innsbruck, Mondsee, Austria.
mSystems
December 2024
Department of Bioengineering, University of California, San Diego, California, USA.
Unlabelled: The composition of bacterial transcriptomes is determined by the transcriptional regulatory network (TRN). The TRN regulates the transition from one physiological state to another. Here, we use independent component analysis to monitor the composition of the transcriptome during the transition from the exponential growth phase to the stationary phase.
View Article and Find Full Text PDFACS Omega
December 2024
School of Psychology, University of Wollongong, Wollongong, New South Wales 2522, Australia.
The biological effects of electromagnetic field (EMF) irradiation in the terahertz (THz) range remain ambiguous, despite numerous studies that have been conducted. In this paper, the metabolic response of K 12 to EMF irradiation was examined using a 1.0 W m incident synchrotron source (SS) in the range of 0.
View Article and Find Full Text PDFIndian J Microbiol
December 2024
Laboratory of BAS Purification and Certification, SPC "Armbiotechnology" Scientific and Production Center, National Academy of Science, Yerevan, Republic of Armenia.
Melanins have immense application potential in the fields of agriculture, cosmetics and pharmaceutical industries. To determine the antimicrobial properties of melanin, conditionally pathogenic bacteria, belonging to different taxonomic groups were used. The results have shown that melanin solution exhibited bacteriostatic or bactericide activity depending on test culture and melanin concentration.
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